Signals of Safety
Crane operators require skilled assistance in order to perform a job well. Performing well means doing it safely. An operator and competent signal person can make a great safety team if they communicate. Proper hand signals, a positive and alert attitude, and a "good eye" for procedures can lessen the risk of accidents or injuries to co-workers.
The designated signal person must be competent and know "all the right moves". As well, the signal person must wear a high visibility vest. armlet, or other clothing that clearly identifies them,. A hand signal chart should be mounted on the crane unit so everyone knows the system. Crane, derrick, and hoisting equipment must be inspected daily. Be on the lookout for faulty equipment such as cracked windshields or a leaking hydraulic line. Good housekeeping on and near the crane area is essential for safety.
Signal Person Duties
Know the basic signals that your company uses. Be sure that you and the operator are using the same signals. Have only one person assigned to be the signaler. More than one will confuse the operator. Also:
Always watch the load - the crane operator is watching you
Make sure the load does not pass above you or other workers
Keep the crane at least 7 metres (20 feet) away from power lines - keep an eye out overhead
Hoist: With forearm vertical, forefinger pointing up, move hand in small horizontal circles.
Lower: With arm extended downward, forefinger pointing down, move hand in small horizontal circles.
Stop: Arm extended, palm down, hold position rigidly.
Emergency Stop: Arms extended, palm down, move hand rigidly right and left.
Raise Boom: Arms extended, fingers closed, thumb pointing upwards.
Lower Boom: Arm extended, fingers closed, thumb pointing downward.
Swing: Point with finger in direction of swing of boom.
Move Slowly: Use one hand to give any motion signal and place your other hand motionless in front of the hand giving the motion signal
A Serious Job
Every worker should know crane hand signals. Knowing the signals may allow you to help out when needed.
If you are asked to be a signal person, make sure you are using the same signals as other workers and operators on the project
With tower cranes or situations where hand signals are not safe enough, ensure that a two-way radio is used for voice communication. This will give you direct contact with the operator.
Whatever system you use - hands or radio - make sure the equipment and workers are able to do the job right.
For more information, refer to current applicable Occupational Health and Safety Legislation
Don't Be a Headline
Listed below are a few Crane Accident stories.
CRANE COLLAPSE KILLS TWO IN ONTARIO
Alves Jose (59) of Winnipeg, Manitoba and Darren Leon (31) of Mississauga, Ontario were killed instantly on June 19, 2000 when a construction crane collapsed at an Oakville water treatment facility. The two men were working on top of a 5 metre wooden wall. The cable on the 40 metre boom snapped as it was lowering a concrete bucket which sent the metal structure crashing on them. Police would not confirm that one man was impaled by a steel reinforcing rod. Two other workers narrowly escaped being crushed while the crane operator was treated in nearby hospital for shock. Reports indicate that around 40 employees of North American Construction Company were working at the Mid-Halton Wastewater Treatment Plant at the time of the accident which was witnessed by dozens. The accident is being investigated by the Halton Regional Police and the Ontario Ministry of Labour.
29 YEAR OLD MAN ELECTROCUTED
A 29 year old worker was electrocuted when he pushed the crane cable on a 1-yard cement bucket into a 7200 volt power line. The victim was a member of a crew that was constructing the back concrete wall of an underground water-holding tank at a sewage treatment plant. Before work on the tank began, the company safety director made sure that insulated line hoses were placed over sections of the power line near the jobsite and that a safe clearance zone was marked off for arriving cement trucks to use for loading their cement buckets.
After the wall was poured, the driver of the cement truck cleaned the loading chute on his truck with a water hose mounted on the truck. As he began to pull away, the crew supervisor yelled at him - asking if the crew could use his water hose to wash out the cement bucket suspended from the crane. The driver stopped the truck under the power line and the crane operator (not realizing that the truck had been moved) swung the boom to position the bucket behind the truck. The victim grasped the power line. The victim provided a path to ground and was fatally electrocuted.
CONSTRUCTION WORKER ELECTROCUTED
A 37 year old construction labourer was electrocuted while pulling a wire rope attached to a crane cable toward a load. The choker was to be connected to a steel roof joist that was to be lifted 150 feet across the roof of a one-story school and set in place. The cab of the crane was positioned 11-1/2 feet from a 7200 volt power line. After a previous roof joist had been set in place, the crane operator swung the crane boom and cable back toward the victim - who grabbed the choker in his left hand. With his right hand, he held onto a steel rod that had been driven into the ground nearby. At this point, the momentum of the swinging crane apparently caused the crane cable to contact the power line. The electrical current passed across the victim's chest and through the steel rod to ground, causing his fatal electrocution.
COMPANY PRESIDENT & EMPLOYEE DIE IN CRANE ACCIDENT
A 20-year old truck driver and his 70-year-old male employer (the company president) were electrocuted when the boom of a truck-mounted crane contacted a 7200 volt conductor of an overhead power line. The incident occurred while the driver was unloading concrete blocks at a residential construction site. The driver had backed the truck up the steeply sloped driveway under a power line at the site and was using the crane to unload a cube of concrete blocks. The company president and a masonry contractor watched as the driver operated the crane by a hand-held remote control unit. The driver was having difficulty unloading the blocks because the truck was parked at such a steep angle. While all three men watched the blocks, the tips of the crane boom contacted a conductor of the overhead power line and completed a path to ground through the truck, the remote control unit, and the driver. The company president attempted to render assistance and apparently contacted the truck, completing a path to ground through his body. He died on the scene. The truck driver was airlifted to a nearby burn center where he later died as a result of electrical burns.